In the following specification and claims, the term "DSP matrix" designates any coherent binder matrix disclosed in the above-mentioned patent applications and comprising
(A) homogeneously arranged inorganic solid particles of a size of from about 50 .ANG. to about 0.5 .mu.m, or a coherent structure formed from such homogeneously arranged particles, and
(B) densely packed solid particles having a size of the order of 0.5-100 .mu.m and being at least one order of magnitude larger than the respective particles stated under (A), or a coherent structure formed from such densely packed particles,
the particles A or the coherent structure formed therefrom being homogeneously distributed in the void volume between the particles B,
the dense packing being substantially a packing corresponding to the one obtainable by gentle mechanical influence on a system of geometrically equally shaped large particles in which locking surface forces do not have any significant effect,
the matrix optionally additionally comprising, embedded therein,
(C) compact-shaped solid particles of a material having a strength exceeding that of ordinary sand and stone used for ordinary concrete, typically a strength corresponding to at least one of the following criteria:
(1) a die pressure of above 30 MPa at a degree of packing of 0.70, above 50 MPa at a degree of packing of 0.75, and above 90 MPa at a degree of packing of 0.80, as assessed (on particles of the material having a size ratio between the largest and smallest particle substantially not exceeding 4) by the method described in International patent application No. PCT/DK81/00048,
(2) a compressive strength of a composite material with the particles embedded in a specified matrix exceeding 170 MPa (in case of a substantial amount of the particles being larger than 4 mm) and 200 MPa (in case of substantially all particles being smaller than 4 mm), as assessed by the method described in International patent application No. PCT/DK81/00048,
(3) a Moh's hardness (referring to the mineral constituting the particles) exceeding 7 and
(4) a Knoop indentor hardness (referring to the mineral constituting the particles) exceeding 800,
said particles having a size of 100 .mu.m-0.1 m,
and the matrix further optionally containing, embedded therein,
(D) additional bodies which have at least one dimension which is at least one order of magnitude larger than the particles A.
The additional bodies termed "D" above are the same bodies as are designated "bodies C" in International patent application No. PCT/DK81/00048. They comprise a wide variety of bodies, including particles such as sand or stone and fibers such as, e.g., glass fibers, steel fibers, and plastics fibers. Particularly strong shaped articles comprising the DSP matrix are obtained when bodies C which have a strength exceeding that of ordinary sand and stone used for ordinary concrete are embedded in the matrix. Typical examples of bodies C are bodies consisting of one or more of the following components: Topaz, lawsonite, diamond, corundum, phenacite, spinel, beryl, chrysoberyl, tourmaline, granite, andalusite, staurolite, zircon, boron carbide, tungsten carbide; one interesting and economical material being refractory grade bauxite.
In the following specification and claims, the term "a material comprising the DSP matrix" designates any material having the new matrix as a binder matrix and optionally containing bodies C and D as defined above. As discussed in International patent application No. PCT/DK79/00047 and International patent application No. PCT/DK81/00048, the particles B will, according to important embodiments, comprise at least 20% of Portland cement particles, preferably predominantly Portland cement particles, and the particles A may, according to important embodiments, comprise ultrafine silica particles ("silica dust") having a specific surface area of about 50,000-2,000,000 cm.sup.2 /g, preferably about 250,000 cm.sup.2 /g, and preferred ultrafine silica particles are particles which are formed by growth from liquid or preferably vapour phase such as particles formed as a by-product in the production of silicon metal or ferrosilicium in electrical furnaces. As described in the above-mentioned patent applications, articles comprising the DSP matrix may be made from an easily flowable composite material of an extremely low liquid content by shaping in a low stress field. In the following specification and claims, the term "composite material" designates any composite material which, on curing, forms a material comprising the DSP matrix. These composite materials are described in greater detail in the above-mentioned patent applications. The composite material containing Portland cement particles as particles B comprises a high amount of a dispersing agent, typically a concrete superplasticizer, and examples of useful concrete superplasticizers are given in the above-mentioned patent applications. The methods and materials for producing, casting and further treating the DSP matrix as diclosed in the above-mentioned patent applications are also used for producing the new matrix in the context of the present application.
In the following specification and claims, the term "densely packed" is to be understood in accordance with the definition of "dense packing" given above.